1. Technical Field
Exemplary embodiments of the present invention relate to a semiconductor device and a method of manufacturing the same. More particularly, exemplary embodiments of the present invention relate to a semiconductor device having improved mobility of carriers in a channel region, and to a method of manufacturing the semiconductor device.
2. Description of the Related Art
Generally, a semiconductor memory device may be classified as either a volatile memory device, such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device that loses data over time, or a non-volatile memory device that continuously stores data over time. Data is rapidly inputted/outputted into/from the volatile memory device. In contrast, data is slowly inputted/outputted into/from the non-volatile memory device. The non-volatile memory device may include an electrically erasable programmable read-only memory (EEPROM) device, or a flash EEPROM memory device, capable of electrically inputting/outputting data. The EEPROM device and the flash memory device are both currently being widely used.
The non-volatile memory device in view of a circuit aspect may be classified as either a NAND type non-volatile memory device or a NOR type non-volatile memory device. The NAND type non-volatile memory device may include unit strings, which include cell transistors serially connected with each other, serially connected between a bit line and a ground line. The NOR type non-volatile memory device may include cell transistors parallely connected between a bit line and a ground line.
Further, the NAND type non-volatile memory device may include a plurality of gate structures constituting the cell transistor, ground selection lines, string selection lines, and common source lines arranged at peripheral regions of the gate structures. Each of the gate structures may include a gate electrode and an active region under the gate electrode.
A voltage may be applied to the common source lines at the peripheral region of the cell transistors to move carriers in the active region. The voltage may be transmitted into the gate structures of the cell transistors and the active region to store and/or erase data by moving the carriers in the active region. However, when there is an increase in the number of the cell transistors, the voltage applied from the peripheral region of the cell transistor may not be transmitted to central cell transistors. As a result, the mobility of the carriers corresponding to the voltage may be reduced.